EAST LANSING — Khari Willis can’t believe how quickly his four years at Michigan State have flown by.

Well, 3½, he is quick to point out. This fall will be his final year as a college football player.

“It’s kind of scary knowing that after this, you’re out and in the real world,” Willis said. “You’ll have to fend for yourself.”

Willis hopes to go out a winner again. And the rest of the 12th-ranked Spartans will be counting on him and his classmates to guide MSU back to the pinnacle of the Big Ten and national rankings.

One year after the Spartans had 13 seniors — nine on scholarship, and three departing starters — they have almost double that this fall, with many of those final-year players in key positions.

There are 18 seniors on MSU’s preseason roster after cornerback Tyson Smith announced Tuesday he would not play this fall because of health problems, and linebacker Jon Reschke was reinstated to the roster after receiving a sixth year of eligibility. Twelve of them finished the 2017 season in the Holiday Bowl two-deep depth chart, and seven of those are returning starters —five on offense and two on defense.

“It’s huge getting everybody back,” senior linebacker Andrew Dowell said Tuesday after MSU’s first practice. “Us older guys gotta use that to teach the younger guys. And the experience that we have can go a long way this year.”

A large part of that comes from players who entered last season as unknown upperclassmen and emerged from a 10-3 renaissance season as key contributors heading into their senior season.

LJ Scott was a proven commodity in his third season at running back. He had a somewhat productive, albeit disappointing, junior season despite leading MSU with 898 rushing yards on 201 carries with eight TDs, but he is expected to be the every-down back this year.

Starting left guard David Beedle, fullback Collin Lucas and tight end Matt Sokol return as seniors who will be working to open running lanes for Scott.

“It feels like last year,” Sokol said of MSU returning 41 of 44 players from the two-deep. “What I’m excited about is for our group to evolve our game up, level up our game as an offensive line, mentally what we can do, and just be smarter play, have a better running offense and be able move guys and make the right calls, have the right communication as a unit. I think that experience coming back is going to be a strong point for us.”

Felton Davis III battled injuries his first two seasons before blossoming last year. The 6-foot-4, 200-pound wideout led MSU’s balanced receiving corps with 55 catches, 776 yards and nine TDs.

He also emerged as a charismatic frontman for a young and talented position group.

“In high school, I wasn’t a vocal leader,” Davis said. “People either followed or they didn’t. But when I got here, people pushed me to be vocal, be vocal, be vocal. And sometimes when you’re not used to that, you’re out there running in conditioning and you’re tired, but you gotta find enough energy for you and the next man beside you.

“People that were here before me did that. It seemed like the better the leaders are on the team, the better the team.”

“I’ve been saying really for six months that this football team is very good with chemistry,” Dantonio said. “It’s as good as I’ve seen, really.”

Willis at strong safety and Dowell at weak-side linebacker are the senior defensive starters, alongside six juniors and a sophomore who are projected to join them as returnees.

However, their other classmates — defensive tackle Gerald Owens, defensive end Dillon Alexander, linebacker Grayson Miller and safety Matt Morrissey — will be vital backups and contributors again in their final fall in Green and White.

Willis said veteran leadership “is one of our strengths,” forged by going 23-4 in 2014-15, surviving the drop of 2016 and helping the reascension a year ago.

“A lot of young guys still, but a lot of leaders, and leaders that don’t start,” said Willis, who joined Scott and junior QB Brian Lewerke in Chicago. “I think those are key as well. I think at every position we have leaders, it’s just a matter of going out and executing leadership to the best of our abilities to bring the younger guys along. …

“Winning games, being with this team, going through that rough season — believe it or not — I wouldn’t trade it.”